<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>vue实例</title>
    <script src="http://unpkg.com/vue@3"></script>
</head>
<body>
    <div id="app">
        <h1>body中的模板</h1>
    </div>

</body>
</html>
<script type="text/x-template " id="temp">
<h1>我是x-template里的模板</h1>
</script>

<script>
    //创建一个vue实例
    const appConn = Vue.createApp({
        // template:'<h1>vue实例中的模板，替换原div的内容<h1>'
            template:'#temp'
    }).mount("#app")   
</script>